1. Field of the Invention
The present invention relates to a digital signal processing circuit which can be applied to a digital audio tape recorder for recording and reproducing a digital audio signal, and the like.
2. Description of the Prior Art
Hitherto, in a magnetic recording and reproducing apparatus, there has been known an apparatus in which a digital audio signal can be recorded and reproduced by using a rotary drum (hereinafter, referred to as a digital audio tape recorder).
That is, upon recording, the digital audio signal is divided into blocks and an interleaving process is executed every block.
Further, after an inner code and an outer code for error detection and correction is formed on a block unit basis, the interleave processed digital audio signal is converted into the recording signal together with the sampling frequency information and time information, and the like (hereinafter, referred to as recording information of the digital audio signal) and is output to magnetic heads.
Due to this, the digital audio signal is recorded into a predetermined area in a main data area. The recording information is converted into subdata and recorded into predetermined areas in the main data area and subdata area.
On the other hand, upon reproduction, the reproduction signal is demodulated by a demodulating circuit and errors in the reproduction data thus obtained are corrected by an error detecting and correcting circuit.
Further, the reproduction data which was subjected to the error detecting and correcting process is subjected to a deinterleave process by an output circuit, converted into an analog signal, and supplied to an output.
At this time, the reproduction data is processed on the basis of the subdata. Due to this, the digital audio signal can be reproduced on the basis of the recording information recorded on a magnetic tape together with the digital audio signal.
Since the recording information is important to processing the reproduction data, in such a kind of digital audio tape recorder, one recording information is repetitively recorded onto the magnetic tape.
Therefore, in the conventional digital audio tape recorder, a check is made to see if the recording information which is repetitively reproduced coincides or not, and the reproduction data is processed by using the recording information in which a coincidence result is obtained.
However, when the magnetic tape is reproduced, it is impossible to avoid the generation of errors. If the reproduction data is merely processed by using the recording information in which the coincidence result was obtained, there is a problem in that it is difficult to process the reproduction data with certainty, and it is necessary to determine whether the recording information is correct or incorrect by additionally using, for instance, an operation processing unit.